Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: CAS:56-25-7 (CAN)
873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reactions of both closo-9,12-I2-1,2-C2B10H10 and closo-9,10-I2-1,7-C2B10H10 with an excess of aryl magnesium bromide in the presence of [PdCl2(PPh3)2] afford the corresponding closo-9,12-(4-R-C6H4)2-1,2-C2B10H10 [R=H (1), Me (2), OMe (3), SMe (4), N(CH3)2 (5), Cl (6)] and closo-9,10-(4-R-C6H4)2-1,7-C2B10H10 [R'=Me (7), OMe (8), N(CH3)2 (9), Cl (10), and -C[(OCH2)2]CH3 (11)] compounds in high yields. The anisole derivatives 3 and 8 were deprotected to yield the corresponding bis-phenols 12 and 13, respectively. Structural analyses of compounds 1, 3, 6, and 12 are reported. Re-etherification of compound 12 by using gamma-bromotriethyleneglycol methyl ether provided 14 (R=(CH2CH2O)3CH3). Oxidation of 4 with ceric(IV) ammonium nitrate (CAN) generated the bis-sulfoxide 15 (R=S(O)Me). Deprotection of compound 11 led to the corresponding acetyl derivative 18 (R'=C(O)Me). Bis-anisole 3 was tethered with 1,3-dibromopropane, 1,6-dibromohexane, 1,8-dibromooctane, 4,4'-bis(iodomethyl)-1,1'-biphenyl, and alpha,alpha'-dibromo-2,6-lutidine to afford the dimers 20b, 21b, 22b, 23b, and 24b, respectively. The tetrameric carboracycles 27a and 30a, as well as the dimeric 29c were obtained through repetitive coupling of the dimeric compounds 20b, 24b, and 22b with 1,3-dibromopropane, alpha,alpha'-dibromo-2,6-lutidine, and 1,8-dibromooctane, respectively. The tetrameric carboracycle 28a was obtained upon consecutive reactions of 1 with 1,4-dibromobutane. Hexameric carboracycle 28b was identified as a byproduct. Exhaustive ether cleavage of 27a generated octaphenol 31a. Re-etherification of 31a with trimethylenesultone provided the octasulfonate 32a, the first example of a water-soluble carboracycle. Linkage of dimer 23b with alpha,alpha'-dibromolutidine yielded the cyclic tetrameric tetrapyridyl derivative 30a in low yield. The structures of the carboracycles 27a, 28a, 28b, and 30a have been confirmed by Xray crystallography. In addition, the compounds 28a,b are the first reported carboracycles that interact with solvent molecules in a host-guest fashion.
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PMID:The synthesis of carboacycles derived from B,B'-bis(aryl) derivatives of icosahedral ortho-carborane. 1286 36

Oxidation of 1-benzyl-3,4-dihydroisoquinolines with cerium(IV) ammonium nitrate (CAN) under mild condition yielded the mixture of corresponding 1-benzylisoquinolines (b-type) and 1-benzoylisoquinolines (a- or c-type) in an equal yields. The selective oxidation products (c-type) can be prepared by using MeCN instead of MeOH. In the antiplatelet assays, four inducers were employed, including AA, Col, PAF, and Thr. In the PAF or Col induced platelet aggregation, compounds belonging to a- and b-type showed stronger inhibitory effects than aspirin.
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PMID:Antiplatelet activity of benzylisoquinoline derivatives oxidized by cerium(IV) ammonium nitrate. 1287 16

Cerium(IV) ammonium nitrate (CAN) has recently emerged as a versatile reagent for oxidative electron transfer; the overwhelming number of reports serve as a testimony to the unparalleled utility of CAN in a variety of transformations of synthetic importance. Our recent work has uncovered novel carbon-carbon bond-forming reactions leading to the one-pot synthesis of dihydrofurans, tetrahydrofurans, and aminotetralins. In addition, we have developed a number of facile carbon-heteroatom bond-forming reactions by the CAN-mediated oxidative addition of soft anions to alkenes. A mechanistic rationale has been provided for the reactions explored. As might be expected of very powerful one-electron oxidants, the chemistry of cerium(IV) oxidation of organic molecules is dominated by radical and radical cation chemistry.
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PMID:Recent advances in synthetic transformations mediated by cerium(IV) ammonium nitrate. 1473 Sep 91

Heating potassium 3-aminobenzo[b]thiophene-2-carboxylate (1) with ethyl propiolate or ethyl 3-ethoxyacrylate in acetic acid yielded the ethyl 2-(6,12-Dihydro-bis[1]benzothieno[3,2-b:2',3'-e]pyridin-6-yl)acetate (3) as main product and 1,4-dihydro-[1]benzothieno[3,2-b]-4-pyridone (2) as by-product. The dihydropyridine (DHP) 3 was dehydrogenated with ammonium cerium nitrate (CAN) to give the pyridine (Py) 4. The half wave potential E(1/2) = 1.64 V showed that 3 was much more stable against oxidizing agents than the reference compound nifedipine with E(1/2) = 1.15 V. Alkaline saponification of the acetic acid ester 4 did not yield the corresponding acetic acid, because decarboxylation took place to form the methylpyridine 5.
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PMID:[Bisbenzothieno[3,2-b: 2',3'-e]pyridines]. 1549 46

There is an ever increasing need to find surfaces that are biocompatible for applications like medical implants and microfluidics-based cell culture systems. The biocompatibility of five different surfaces with different hydrophobicity was determined using gene expression profiling as well as more conventional methods to determine biocompatibility such as cellular growth rate, morphology and the hydrophobicity of the surfaces. HeLa cells grown on polymethylmethacrylate (PMMA) or a SU-8 surface treated with HNO3-ceric ammonium nitrate (HNO3-CAN) and ethanolamine showed no differences in growth rate, morphology or gene expression profiles as compared to HeLa cells grown in cell culture flasks. Cells grown on SU-8 treated with only HNO3-CAN showed almost the same growth rate (36 +/- 1 h) and similar morphology as cells grown in cell culture flasks (32 +/- 1 h), indicating good biocompatibility. However, more than 200 genes showed different expression levels in cells grown on SU-8 treated with HNO3-CAN compared to cells grown in cell culture flasks. This shows that gene expression profiling is a simple and precise method for determining differences in cells grown on different surfaces that are otherwise difficult to find using conventional methods. It is particularly noteworthy that no correlation was found between surface hydrophobicity and biocompatibility.
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PMID:Whole genome expression profiling using DNA microarray for determining biocompatibility of polymeric surfaces. 1715 39

Use of imidazolium ionic liquids as solvents for organic transformations with tetravalent cerium salts as oxidizing agents was evaluated. Good solubility was found for ammonium hexanitratocerate(IV) (ceric ammonium nitrate, CAN) and cerium(IV) triflate in 1-alkyl-3-methylimidazolium triflate ionic liquids. Oxidation of benzyl alcohol to benzaldehyde in 1-ethyl-3-methylimidazolium triflate was studied by in-situ FTIR spectroscopy and 13C NMR spectroscopy on carbon-13-labeled benzyl alcohol. Careful control of the reaction conditions is necessary because ammonium hexanitratocerate(IV) dissolved in an ionic liquid can transform benzyl alcohol not only into benzaldehyde but also into benzyl nitrate or benzoic acid. The selectivity of the reaction of cerium(IV) triflate with benzyl alcohol in dry ionic liquids depends on the degree of hydration of cerium(IV) triflate: anhydrous cerium(IV) triflate transforms benzyl alcohol into dibenzyl ether, whereas hydrated cerium(IV) triflate affords benzaldehyde as the main reaction product. Reactions of ammonium hexanitratocerate(IV) with organic substrates other than benzyl alcohol have been explored. 1,4-Hydroquinone is quantitatively transformed into 1,4-quinone. Anisole and naphthalene are nitrated. For the cerium-mediated oxidation reactions in ionic liquids, high reaction temperatures are an advantage because under these conditions smaller amounts of byproducts are formed.
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PMID:Imidazolium ionic liquids as solvents for cerium(IV)-mediated oxidation reactions. 1722 69

Perfluoroisopropyl carbanions generated in situ by treatment of perfluoropropene (HFP) with solid KF in the appropriate solvents add to N-alkylpyridinium, quinolinium, and other azinium salts to give reasonably stable N-alkyldihydroazines containing a perfluoroisopropyl group. In most cases, addition proceeds in position 2 of the heterocyclic ring. Stability of these dihydroazines depends on the nature of the N-alkyl group and other substituents present in the azine ring. The least stable of them were converted into their stable C-trifluoroacetyl derivatives in reaction with trifluoroacetic anhydride. Treatment of N-benzyl- or N-p-methoxybenzyl-2-perfluoroisopropyl dihydroazines with oxidizing agents such as DDQ or cerium(IV) ammonium nitrate results in cleavage of the benzylic C-N bond followed by oxidation of the ring, giving pyridines or quinolines with a perfluoroisopropyl group in the aromatic ring. On the basis of these findings, a new protocol for introduction of perfluoroalkyl substituents into azine rings was elaborated via oxidative nucleophilic substitution of hydrogen. It involves three chemical steps: (i) alkylation of azine with p-MeOC6H4CH2Br, (ii) reaction of the resulting salt with fluorinated carbanions generated in situ from HFP and KF, and (iii) N-deprotection and aromatization of the isolated dihydroazine on treatment with CAN. The first two reactions, (i) and (ii), can be performed as a one-pot operation.
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PMID:Synthesis of perfluoroalkyl-substituted azines via nucleophilic substitution of hydrogen with perfluoroisopropyl carbanions. 1724 22

It is shown that the N-(p-ethoxyphenyl) group on beta-lactams can be oxidatively removed by ceric ammonium nitrate in good yield. Fourteen new N-(p-ethoxyphenyl)-2-azetidinones 8a-n were synthesized through standard [2+2] ketene-imine cycloadditions (Staudinger reaction). Treatment of these compounds with ceric ammonium nitrate yielded the N-dearylated 2-azetidinones 9a-n in good to excellent yields. The effects of solvent, molar equiv of CAN and different temperatures have been investigated and optimum conditions were established.
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PMID:Synthesis of novel N-(4-ethoxyphenyl) azetidin-2-ones and their oxidative N-deprotection by ceric ammonium nitrate. 1797 63

The reaction of cerium(IV) ammonium nitrate (CAN) with a range of N-(p-anisyl)azoles in acetonitrile or methanol solvents leads to N-dearylation releasing the parent NH-azole and p-benzoquinone in comparable yields. The scope and limitations of the reaction are explored. It was successful with 1-(p-anisyl)pyrazoles, 2-(p-anisyl)-1,2,3-triazoles, 2-(p-anisyl)-2H-tetrazoles, and 1-(p-anisyl)pentazole. The dearylation renders the p-anisyl group as a potentially useful N-protecting group in azole chemistry. The azole released in solution from 1-(p-anisyl)pentazole is unstable HN5, the long-sought parent pentazolic acid. p-Anisylpentazole samples were synthesized with combinations of one, two, and three 15N atoms at all positions of the pentazole ring. The unstable HN5/N5- produced at -40 degrees C did not build up in the solution but degraded to azide ion and nitrogen gas with a short lifetime. The 15N-labeling of the N3- ion obtained from all samples proved unequivocally that it came from the degradation of HN5 (tautomeric forms) and/or its anion N5- in the solution.
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PMID:A ceric ammonium nitrate N-dearylation of N-p-anisylazoles applied to pyrazole, triazole, tetrazole, and pentazole rings: release of parent azoles. generation of unstable pentazole, HN5/N5-, in solution. 1819 92

The cerium(IV) ammonium nitrate (CAN)-catalyzed sequential, one-pot reaction between alkylamines, beta-ketoesters, and chalcones afforded cis-4,6-disubstituted 2-alkylaminocyclohexene-1-carboxylic esters with complete diastereoselectivity. The carbon-carbon double bond of these compounds was reduced with sodium triacetoxyborohydride, again with complete diastereoselectivity. This novel two-step route allows the transformation of very simple acyclic starting materials into tetrasubstituted cyclohexane derivatives bearing four functional groups, including a cis-beta-aminoester moiety, and generates four stereocenters, three of which are adjacent and one of which is quaternary.
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PMID:Two-step stereocontrolled synthesis of densely functionalized cyclic beta-aminoesters containing four stereocenters, based on a new cerium(IV) ammonium nitrate catalyzed sequential three-component reaction. 1877 79


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